1) Field of the Invention
The present invention relates to an access-request control method of controlling requests from respective applications to access to a communication device to which at least a general-purpose port is allocated and which responds to the access requests from the applications so as to communicate with the applications via a communication network, a driver program for a communication device, and the communication device. More particularly, the present invention relates to an access-request control method of permitting an access to the communication device where the general-purpose port is allocated only to a specified application of the applications so as to prevent a false access or an improper access from another application to the communication device, a driver program for a communication device, and the communication device.
2) Description of the Related Art
Conventionally, a Windows (registered trademark)-installed personal computer (PC) include a communication (COM) port (serial port) as a general-purpose port, and devices referred to as PC cards such as a modem card having a modem function and a wireless communication card having a wireless communication function are allocated to the COM port.
When a PC card is allocated to the COM port, various applications that are actuated on Windows can access to the PC card via the COM port. For example, when a modem card is connected to the PC and is allocated to a COM2 port, a general-purpose application that uses a modem such as a HyperTerminal can access to the modem card via the COM2 port.
When, however, all the applications are set so as to access to the PC card allocated to the COM port because the COM port is the general-purpose port, problems arise when a certain application erroneously accesses to the PC card or an improper application accesses to the PC card. Specifically, conventional PC cards and device drivers (serial drivers) for the PC cards cannot check the type of the application that accesses to the PC cards via the COM port. Therefore, even an application that is not permitted to access to the PC cards can access to the PC cards via the COM port.
Serious problems may arise with PC cards having a multi-access function of simultaneously establishing voice communication and packet communication. Specifically, when such a PC card is connected to a PC, a COM port is allocated to the PC card, and a website is browsed by using the packet communication of the PC card, if an improper application that is described by Java (registered trademark, same applies hereinafter) script is downloaded from the website, automatic dial-up connection is established via the PC card by actuation of the improper application, and a user is later charged for an unintended telephone bill.